Symmetry

When discussing symmetrical maps, forgers think of maps where both
halves are mirror images of each other. But symmetry is more than just
the layout of a map. At the core of symmetry is the forger’s ability to
enforce the rules of the game. And I think it can help to see how
symmetry is used in sports to better understand how and why it is used
in level design.

Symmetry In Sports

Basketball is a fully symmetrical game.
From the initial toss of the ball at the center of the court (the
initial rush) to the conclusion of the game, each team is afforded
exactly the same opportunities. The game is played on a fully
symmetrical court. The reflective translation of the court’s layout
provides equal distance and equal effort to each team’s hoop regardless
of where you begin along the court’s center plane. All of this creates
pure symmetry in the Game Play itself to ensure unquestionable fairness
through continuous equal opportunity to score, since both teams can
score at any time.

Baseball is a fully asymmetrical game. Each
team plays only one role (offense or defense) during a single Round,
switching roles every Round. Two consecutive Rounds are called an Inning.
The game is played on a dramatically asymmetrical field, where defense
has free roam everywhere except the batters’ box, and the offense has
both exclusive access to the batters’ box and shares only the Paths
between the bases with the defense. In Baseball, there is never equal
opportunity to score at any one moment in time, for only the offense can
score. Rather, opportunity to score is balanced through the aggregation
of any one pair of Rounds.

Football is a blend of symmetry.
Asymmetrical properties of the game include a first and second half,
essentially two Rounds. Each half starts with a kick off in which each
team is the kicking team only once. The teams also change ends of the
field to balance any benefits that the wind may offer. And each team
plays a role of offense or defense, where the ball is owned by the
offense. Symmetrical properties include the field layout, both teams can
score on any play, and the asymmetric roles can change any number of
times for any length of time.

Pool is the fourth example of a sport that I
want to introduce, because it has a very interesting dynamic that is
also found in a couple of Halo Game Types. Like Football, Pool is a
blend of symmetry. One person plays at a time (one person is offense at a
time and only he can score), and the changing of the roles (who can be
the shooter) can change any number of times and at any time. But what
makes Pool very different is that the player who is shooting is winning,
because until he misses and loses his turn, he is the only person who
can score.

Symmetry In Halo

When we talk about symmetrical maps and asymmetrical maps, we are
talking about how the Geometry, the Spawns, and the Weapons are laid out
to establish either perfectly equal opportunities to yield an
unquestionably fair game; or to establish the two ends of the map
uniquely for the roles of offense and defense, regardless of how
different the two ends compare with each other. In this respect, it is
actually going to be easier to discuss asymmetry in Halo first, because
there are just a few true asymmetrical Game Types that we need to cover.

One Flag, One Bomb, Territories, andInvasion
are all examples of fully asymmetrical Game Types. Like Baseball, the
goal is never to establish equality of play, but to promote unequal Game
Play through team roles, while seeking fairness through the pairing of
complimentary Rounds. For these Game Types, map symmetry is neither
required nor desired; but rather dramatic asymmetrical Geometry
supporting the role.

Static Spawning is required; yet the Spawn layout for each team is
driven exclusively by the surrounding Geometry and not in any way by
each other. Weapons can be placed in the middle of the map for an
initial rush, but this is not necessary. Instead, each team has their
own weapons and vehicles uniquely chosen to aid them in their roles.

For Invasion, the asymmetry goes a step further, and each team plays
Invasion as a unique race depending upon their role on the given map;
and the weapons and vehicles for each role match the race for that role.

Juggernautand Living Dead
are the most extreme of asymmetrical Game Types that I can think of in
Halo. Not only does each team have unique roles, but the population of
each team is different and dynamic. In each Game Type, players of one
team can switch to the other, and the two teams are typically
unbalanced.

It is these Game Types that I feel Pool makes the best analogy. So
long as a player is a human in a Living Dead (Flood) Game Type, he is
winning. Why do I say that? Because he can rack up pretty much endless
kills. Once he becomes a zombie (or the Flood in Halo 4), there are only
so many points that he can accumulate.

The same is true with the Juggernaut. So long as a player is the Juggernaut, he can score.
For these Game Types, there are no symmetrical requirements for the
map. Dynamic Spawning is best; and there are no initial rushes for power
weapons, because the weapons used are restricted to each team’s role.

All other Game Types are symmetrical,
because they require both teams to continuously play the dual role of
offense and defense, just like in Basketball. And it is this dual role
that requires equal opportunities at all times in order to establish
fairness of Game Play. But as with any rules, if you can make the Game
Type play better in other ways, you should.

Slayerand all of its variants are
symmetrical Game Types for the reasons given above. The key difference
between the Slayer variants and other symmetrical Game Types is that
Slayer has no objective.

CTF, Neutral Flag, Assault, Neutral Bomb, Ricochet, andStock Pile
are all examples of symmetrical Game Types for which the objective has a
corresponding goal that is fixed to the bases; and with the exception
of some Stock Pile implementations, their objectives never move across
the map during Game Play.

KOTH, Odd Ball, Land Grab, Head Hunter, and Extraction are all examples of symmetrical Game Types for which the objective moves across the map during Game Play.

Categorizing the symmetrical Game Types like we did shows us patterns
common between various Game Types. And those patterns have differing
levels of needs for symmetry. What works for CTF will work just as well
for Ricochet for all the same reasons, but not for KOTH or Slayer. So
let’s look at how to forge for these Game Types.

Symmetrical Maps

Symmetrical maps come in two flavors.

Reflective Translation is what we would
call a mirror image, where a map is divided down the center and each
half is a reflection of the other across the center plane. This is the
more common form of symmetrical Geometry, but it carries the stigma of
being too simple, too artificial, and too symmetrical to enjoy. Some
maps, like Narrows, Haven, Construct, and Countdown, can pull off
Reflective Translation so well that the symmetry seems natural and
compelling. (I will talk more later about why they succeed so well.)

Yet, players love asymmetrical maps, because they look more natural –
they are more interesting to play on. You can forge a symmetrical map
and try to make it look asymmetrical by using different materials on
each half. I saw one map where one base was forged out of rocks, while
the other base was forged from blocks. They were Geometrically
identical, but they looked very different. This approach also helps with
orientation, because a player can identify which end of the map they
are on by the materials surrounding them.

Another approach to hiding symmetry in a fully symmetrical map is to forge a Rotational Translation
map. This is a map in which both halves of the map are identical to
each other, but rotated 180 degrees around the center of the map. Asylum
was the best example of this type of symmetry. Both teams saw exactly
the same terrain before their bases – rocks on the right, and an open
area on the left. Traversing either side of the map leads to different
terrain as you cross the map’s center plane.

Rotational Translation maps fall short in one way, however. While any
point along the center plane is equal distance from each base, the
differences in terrain prevent them from being equal effort from either
base. If a Hill, a Territory, Odd Ball Spawn, or a Head Hunter goal is
to be equal distance and equal effort to both teams’ bases for a fully
symmetrical experience, then they must be forged along the center plane
of a Reflective Translation map.

Deciding The Map’s Symmetry

At this point you understand the need for full symmetrical Game Play
to establish fairness for symmetrical Game Types; and that forging the
symmetrical Game Types that have moving objectives requires both equal
distance and equal effort from each teams’ bases. But is it truly
practical to expect the majority of Game Types to be offered only on
Reflective Translation maps? The argument would come down to how much
fun is lost to the symmetry? And this in turn takes us to the Football
analogy – can we forge a blend of symmetry to make these Game Types more
interesting and fun to play?

Reflective Translation offers perfect balance and ultimate fairness,
but nearly always at the price of boredom. Rotational Translation offers
perfect balance and ultimate fairness so long as the Game Type doesn’t
require moving objectives across the center plane, and to some degree a
touch of boredom (symmetry cannot be hidden completely). And
asymmetrical maps offer the best opportunity to captivate the
imagination of players, but offers the forger the greatest challenge to
achieving near balance and fairness. If you choose to implement any
symmetrical Game Type on an asymmetrical map, realize your number one
driver is to create an environment so thrilling to play on with so
little imbalance that what imbalance your map has is easily overlooked.
So long as you achieve a great experience and you truly minimize
imbalance, your map will be taken seriously.

Regardless of the map’s symmetry or lack there of, there are important considerations to keep in mind.

Spawning

For those symmetrical Game Types that have base fixed objective
goals, Static Spawning is required regardless of the symmetry of the
map. This ensures that a team will always Spawn near their team’s base
and never at their enemy’s base.

For all other symmetrical Game Types, Dynamic Spawning is usually
preferred. In fact, I would argue that Dynamic Spawning is necessary for
asymmetrical maps, because it helps balance access to key parts of the
map. If there is a benefit to north end of the map, it wouldn’t be fair
to allow only the blue team to spawn at that end all the time. Dynamic
spawning helps balance out the spawning across the map and all the
opportunities that come with it.

Minimize Imbalance

If you choose an asymmetrical map, you will need to work extra hard
to minimize imbalance through out the Game Play. This is where things
can get tough. While testing you will not be able to prove you
discovered every imbalance your map has to offer. You can only discover
imbalance, but you can’t know what it is you haven’t discovered yet.

Regardless of the symmetry of the map, initial rush for Power Weapons
should still be on your map, and they should all be at the very least
equal distance and as much equal effort from initial Spawns as possible.

Moving Objectives

Let’s step back and talk about the difficulties of forging the
symmetrical Game Types whose objectives move across the map. We talked
about how if you use a symmetrical map for the purpose of fairness, then
it must be a Reflective Translation map, because Rotational Translation
maps don’t offer equal distance and equal effort together. But quite
often even the perfect Reflective Translation map will make a Game Type
like KOTH boring, because the Hills are always on the center
plane of the map. So if you are like me you want to scratch the entire
idea of attempting to forge a symmetrical map to forge these Game Types
on. That leaves you with asymmetrical maps, or maps that are more
interesting. This forces you to focus on making the map so interesting
to play on that any imbalance that may be perceived is accepted as
necessary to make the Game Type playable – to make it a lot of fun!

A far more interesting experience is an apparent random scatter of
objectives across the map. For this reason you do not want Static
Spawning, because you never want one team to have an advantage over a
given Hill, Territory, or zone. Dynamic Spawning is best in these cases
to allow players generally equal access to all parts of the map upon
Spawn, and it also penalizes death by making the player spawn further
from the action.

In these kinds of maps, you may also want to consider where you place
the power weapons. If you place them away from the objectives, you tend
to increase the opportunity for Spawning players to acquire them. This
can help prevent the game from turning lopsided.

Additionally, if a power weapon spawns at a distance from a Hill,
then a spawning player may be torn between trying to take the Hill
quickly or rushing the power weapon to help him take the Hill a little
later. These kinds of difficult decisions can make your map more
interesting to play on.

Summary

Symmetry is a key to enforcing the rules of a game and fairness of opportunities.

Making a Game Type enjoyable to where it becomes truly playable is just as important if not more so.

In each Game Type, there are Spawning rules and other formulas you need to follow to have your map taken seriously.